The process of the present invention is an efficient method of resolving 1-aminoindanes into the R-isomer. The process is a simple method which gives high yields of the desired isomer.
In contrast the method in the literature gives a low yield. That resolution uses N-acetylleucine as the resolving agent and uses an aqueous solution. In 100 consecutive crystallizations of the salt obtained by combining equimolar quantities of DL-1-aminoindane and L-(-)-N-acetylleucine it was possible to obtain the R(-)-1-aminoindane L-(-)-N-acetylleucine from which R(-)-1-aminoindane and the R(+) hydrochloride were obtained. Low yield prompted attempts to recover and fractionally crystallize the salts present in the mother liquors of the resolution. Bull Chim e Farm 115: 489-500 (1976).
In the present invention the resolving agent used is R-N-acetyl-3,4-dimethoxyphenylalanine which is disclosed in U.S. Pat. No. 3,734,952 but not used as a resolving agent.
The process of the present invention may be used for producing intermediates in the synthesis of indanyladenosines which compounds are described in U.S. Pat. No. 4,501,735 herein incorporated by reference.
The present process gives greatly improved yield, 83% yield of R(-)-1-aminoindane compared to very low yields in the process described above.